Jaw holder



p 1952 J. H. KINDELBERGER 2,609,860

JAW HOLDER Filed March 7, 1949 2 SHEETS-SHEET 1 1N VEN TOR.

ATTORNEY J. H. K/NDEL BERGER 1 s Bi 1 Sept. 9, 1952 J. H. KINDELB ERGER JAW HOLDER 2 SHEETSSHEET 2 Filed March 7, 1949 FIG. 6

INVENTOR. J. H- K/NDELBERGER BY weal x/ML ATTORNEY Patented Sept. 9, 1952 James H..Kindelberger, Pacific Palisades, Calii-L, assignor toNorth American Aviation, Inc.

Application March 7, 1949, seriainoxsaoss 9 claims. (01. 153-48) This invention pertains to a jaw-holding devic for use in stretching and forming machines. Machines of the type illustrated in U. S. PatentNo. 2,357,027, issued to R. Seifried "for Bendingand Beveling Madhinefareadapted to grip material,

provide a jaw-holder so constructed that satisfactory forming may be obtained by a short grip on the material.

It is a further object of this invention to provide a jaw-holder so constructed that jaws carried thereby are arranged with respect to the material so as to prevent wrinkling and spoilage.

It is yet another object of this invention to provide a jaw-holder having a wide variety of jaw arrangements but requiring a minimum of adjustment.

It is still another object of this invention to provide a gripping arrangement which enables the use of sheets of material that are approximately the length of the finishedssheet.

Further objects of inventionwill becom'eapparent from the following description taken in connection with the accompanying drawings, in which:

Fig, 1 is a perspective view of the invention; Fig. 2 is an elevational view of the jaw-holder;

Fig. 3 is a sectional view substantially along the line 3-3 of Fig. 2;

Fig. 4 is a view similar to Fig. 2 with parts in an extreme adjusted position;

Fig. 5 is an elevational view of a jaw adapted for use with the present invention; and

Fig. 6 is an elevationalview of a modified jaw adapted for use with the present invention.

Referring now to the drawings, there is shown a jaw-holder I comprising a back-up plate 2 pivotally connected at 3 to a clevis 4 which in turn is adapted to be operatively connected to a cylinder (not shown, but which may be a part of the stretch forming machine illustrated in mentioned patent). Pivotally attached to backup plate 2 are a pair of elongated jaw-holder plates 5, each of which has a plurality of slots 6 of suitable shape for slidably and rotatably receiving" sheet-gripping jaw 1, such jaw per so being of conventional structure and having integral therewith a shank 8 and an enlarged portion 9 adapted to he slid- '2 ably received in slots 6. Nut I is adapted to be screwed into'clamping position with the face of member for holding the jaw in adjusted pos'ition. i

Fig. 1 of the drawing shows the jaws'gripping a sheet of material I l in position to form it against die 12.

Referring now-to Figs. 2 and 3, jaw-holder plates 5 are pivotally connected by bolt l3 and nut M to backup plate 2. The backup plate is provided with recesses I 5 for adjustably receiving boltlS, permitting the jaw-holder to be shifted laterally upon loosening of the nut l4 and pivoting of jaw-holder plates 5. Thispivoti'ngand sliding movement of plates "5 with respect to backup plate, 2 is accomplished by screw thread l6 whichactuate's worm gears I1 pinned respectively to jaw-holder plates 5. Openings I8 are adapted to receive jaws I having relatively longshanks or pivotm'eans 8' so that portion thereof may fit in slots 6a contained in backup plate 2. This {arrangement serves'to hold the backup plate jaws being held in their preselected position by rotation of nut l0 into clamping position. Sheet material I i is then attached to the jaws, stretched to'about its yield point, and then wrapped or formed against die member l2.

In the arrangement illustrated in Fig. 4 the openings I8 are positioned adjacent the lower edge of plates 5 in order to provide a relatively wider range of adjustment of the jaws than is possible with the openings positioned as in Fig. 2. The pivot I8, as illustrated in Fig. 2, may be said to lie substantially on the longitudinal axis of the jaw holder plate, whereas in the arrangement illustrated in Fig. 4, the pivots may be said to be located eccentric to the longitudinal axis of such plate.

Although the invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only and is not to be taken by way. of limitation, the spirit and scope of this invention being limited only by the terms of the appended claims.

I claim:

1. A jaw holder for a stretching and forming machine of the typehaving jaws for gripping a sheet of material, stretching the same to about its yield point, and forming it about a curved die, said holder comprising a backup plate adaptjaw holder plate is provided with a plurality of I I slots for laterally adjustably receiving said jaws. ,1,

3. A device as recited in claim 1 in which'said jaw holder plate is provided with slots for slidably and rotatably receiving said jaws, said jaws type having jaws for gripping a sheet of material, stretching the same to about its yield point, and forming it about a curved die; a jaw holder adapted to extend in a direction generally along an edge of said sheet, a plurality of jaws carried by said holder and projecting toward said sheet, means on said holder for adjustably positioning said jaws laterally of said holder infa"5plane generally transverse to the plane of the sheet and into positions "corresponding to the curve of the sheet when in its formed position and means for retaining said jaws in their adjusted positions on said holder during the stretching and forming operation.

enlarged portion for engagement in said slots.

4. A jaw holder for a stretching and forming machine of the type having jaws for gripping a sheet'of material, stretching the same to about itsyield point, and forming it about a curved die, said holder comprising a backup plate adapted to extend generally along an edge of said sheet, jaw holder plates pivoted on said backup plate to move generally transverse to the plane of the sheet, jaws adjustably carried by the jaw holder plate and projecting toward said sheet, and means connecting each of said jaw holder plates to said backup plate comprising pivot means and a pin and slot connection spaced from said pivot means for adjusting the posi tions of said holder plates with respect to said backup plate. Y

5. A device as recited inclaim 4 in which each of said jaw holder plates-is elongated along its longitudinal axisand said pivot means for each of said jaw holder plates lies substantially on said longitudinal axis.

6. A device as recited in claim 4 in. which each of said jaw holder plates is elongated along its longitudinal axis and the pivot means of each of said jaw holder plates is located eccentric to said longitudinal aXis.

7. A device as recited in claim 4 and further including means carried by said backup plateand engaging said holder plate for adjusting said jaw holder plates ,laterally and rotatably about said pin and slot' connection and for holding them in adjusted position.

8. In a stretching and forming machine of the 9. In a stretching and forming machine of the type having jaws for gripping a sheet of material, stretchingthe same to about its yield point, and forming'it about a curved die; a jaw holder, a plurality of jaws mounted on said holder and projecting toward said sheet, means on said holder for pivotally and laterally positioning said jaws with respect to said holder in a plane generally transverse to the plane of the sheet and to a position corresponding with the position of the portion of the sheet of material which it grips when in the formed position thereby to initially bend the sheet laterally prior to the stretching and forming operation, and means for holding said jaws in their adjustedposition on said holder during the stretching and formin operation,

' JAMES H. KINDELBERGER:

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 401,509 Mitchell Apr. 16, 1889 508,732 Mason Nov. 14, 1893 680,840 Caldwell Aug. '20, 1901 776,685 Post Dec. 6, 1904 776,686 Post Dec. 6, 1904 991,781 Holmquist May 9, 1911 1,441,901 Anderson Jan. 9, 1923 2,269,549. Oeckl Jan. 13, 1942 2,357,027 Seifried Aug. 27, 1944 2,378,413 Lermont June 19, 1945 2,437,092 Greene A Mar, 2, 1948 

